Acoustic tile



Y 106. COMPosmoNs,

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1 Thisj invention relates to acoustic tilesn which thel 'body particles are bonded together -hy means .ofan'adhesive It is the object of this invention to provide an l W" acoustic tile of ,ceramic material, lespecially i,` y 5 'materiaL'which is'ofV a resilient 'charf'fAcoustic Y'tiles may'jbe made by cementig Q A Body particles together at their points of contact 6r' `by 'shrinkiifis'4 the cementtious binder so as to 0 lal'xive(V intercommunicating passages between the bddy'puticlesf-Suchiiles `may 'be made y of 'a' variety ',Qfjjmaterials; both fibrous and uch titlesv may be made I of asbestos mineral wool sla wool, glass wool :mmm y Et't'enztnls'mMoV various" shapes and sizes; etc.v These are'lionded 'together by -a suitable .binderV 90 cir' cement; plaster of and Sodium silicate extensively; IA of bindervis used, usually enough jbeng used to bind 'the vrlzilestigether atth'eii Points of contactpto t L# n byrroduoe'atile'of maximum porosity and 85 or i astio. *sound-absorption eilli'.-

i* wat gilnayy he subjected to bressure and vthe a i intercommuriictingpassages betweentfie'bddy 30 particles 'substantially completely eummstei.' in another'modcatiun employing similar material, frange-oi sizes prpgrt'icles 1s useqso that the i u iiiteioornmniiicatin'g passges'betweli'the larger l1; pa'ijticles'are vsubstantially conglpletelyjlled with smallervparficleS-l .i The 'bonding seems which. ,haveen J11Std, usually arytb a brittle hardijiess. 5 The L un; tile isinrittle, especially if 'nlv the points offcon-f e 3'@ tct are?!r cementecl together! and must hamilecl 40 refunyfbe'fore sind duringV erectioniinlnrder i1: have round that if 'Ys-smqubmuunt of 1' rubber .distributed or dispersed @formo-throughout 45 the ibmmnsagent, #tnt Vresulting;twmxst'ic me. Femmes lbrie reslierit end' uthStP-ndsgougfirl handling turingA "manufaemessmpment end 'f Cross eforen@ mmf-Application Januvyfpofisss, 1

t grar'iularfiaterials'fand "also inixtures of these:

cri@` ed mineral iEaiclesi l l uzmcev own. roc s ne,- the rubber dispersed for a considerable erid lof clay pruce 'n isi, assigner to C. i'. t I- l (chiot-*zii 1 such 'solution asa'binderffor tiles, the tile becomes brittle and does `not possess lthe good streets obtainedwnen the rubber is maintained in uniformly dispersedw'ondition in the silicate. I have discovered afmethoi 1{vhereby the rubber 'may be kiewunifvmly dispersed@ the 'alkali silicate solutions, lespecially the' more viscous so# lutions, without'appreciably decreasing `the atl- 7 Ihesive propertiesr ofA the silicate. "jfurthermorel my mihol'increases the Water resistance' ofthe silicate. method-isthe subject of 'my-Jep# ending sopliiion lSW1 Noaas ,meid 33119120 11933:? :is n I V 'lttltnw u; ,iIf ,a rubbersvlufin "r .A'Slspensioe latex; fispers'ed in a "sodiurnfsllicate- 'l solution of high viscosity; itis 'lossibletukeep Ytutti s;

time',- usually to llow' the alkali 199. its@ Selm PSU@ manger., and for the usual mirposesiffjhave fuxd that Examiner that thettlitan smette may se manipulated 'anti e 106. COMPoslTloNs, 7 5 comme 0R PLASTIC.

solubility of the silicouorides apparently is a desirable property.

'I'he alkali silicate preferably is one which is of medium alkalinity-an SiO: to NazO ratio of 3.25 to 1 gives excellent results. Other ratios may be used although those with a higher SiOz ratio gel more rapidly when the gelling 'agent is mixed with them. The alkali silicate solution preferably is a concentrated one, that is, the

higher viscosity. For example, a 3.25 to 1 SiOr to NazO ratio silicate preferably should have ai specic gravity of 40 B.or over.

The effect of the dispersing agentis .clear-1y" shown when the alkali silicate solution is examined under a microscope. Without the dis? persing agent present the rubber particles coa' lesce rapidly and form relatively large' bodies. With the dispersing agent present the particles remain dispersed.

.Although the amounts of rubber solution or latex and dispersing agent may be varied over wide limits, it is desirable to keep the amounts of these used as low as possible because of their relatively -high cost. For most adhesive pur-- poses the amount of rubberV latex, based on 60% rubber content in an ammoniacal solution need not exceed 20% of the alkali silicate solution and preferably it should be less than 10%. As little as 1% of rubber latex may be used with good effect. Usually it is not feasible to use more than 10% o of the detrimental o e s ca e. This amoun OWeVeI, Epen 35.' `1`pl't"'r1"the.-type of silicate used, and the silicate of the previous example, 5 parts o permissible amount increases with increasing NazO content. I prefer to use alkali silicofluoride in an amount less than 5% of the-weight of the alkali silicate solution. Sodium silicofluoride in an amount equal to about 50% of the weight of 60% latex solution used is a convenient ratio which may be used. A sodium silicate solution containing 5% of latex and 275% of sodium silicouoride has given excellent results as an adhesive in making the tiles of this invention. As little as 1% and as high as 5% of silicouoride may be used with good results. The resulting product, especially if dried at 100 to 150 C. is resistant to the action of water. The water resistance increases with increase of dispersing agent. 'I'he nely dispersed `rubber gives the product a resilience which is desirable for many purposes.

In a speciic example an vacoustic tile was made lof a mixture consisting of 150 parts by weight of porous slag particles which passed through a 4 mesh screen and were retained on a 28 mesh screen, and an adhesive consisting of an intimate mixture of 145 parts by weight of a 3.25 to 1 ratio sodium silicate solution of 42 B., 4 parts of a 60% rubber latex solution, 'and 3 parts of powdered wlice. After the above mixture is forme pe it is dried. Y 'I'he result is a somewhat resilient structure with pores and intercommunicating passages. -Pumice or other aggregates may be substituted for the slag and an equivalent rubber solution, such'as Vrubber cement, may `be .sub stituted for the rubber latex. 1

, I n another lexample exfoliated vermiculit -is used. Y 125 parts of ex-toaa vemte screened to pass through a 4 mesh screenand to stay on an 8 mesh screen are mixed with an adhesive consisting of 125 parts of the sodium Cross rubber latex and 5 parts of wdered sogum sgiciie. The mixturei ape an le hide am'Hne or other suitable solventI may' 'Be .suti'tuted f solution is of a molasses consistency or of still I.

"solutions do not seem to work as smoothly as the cference m e usua way.

It is obvious that various body particles may be used and that the proportions of the constituents may begchanged to vary the` physical properties Vofthe acoustic tile.

A solution of rubber in bonzol carbon" disulor the rubber latex. However, such Ecolloidal rubber latex suspension and therefore latex is the preferred material.

v Throughout the claims wherever rubber or .latexis speciednuantitatively, it refers to a 60% solution or an amount of latex of diierent concentration containing an equivalent amount of rubber.

rWhenever, a gel is referred to, it refers to any of the jelly-like products which may result from the -gelling of an valkali silicate ysolution by the slow-acting chemicals mentioned herein, and formed by any or all of the methods described herein. i,

.1. `An acoustic :tile consisting of body parf; tcles bonded together with an adhesive comprising avalkali silicate containing rubber substantially uniformly dispersed throughout to form intercommunicating channels and pores between said body particlessaid adhesive com--y prisingthe product resulting from the drying of a -concentrated alkali silicate solution containing not'more than 12 percent of vrubber Aand a silica gel uniformly dispersed throughout. 2. The acoustic tile of vclaim 1 in which ,the Effi particles are of mineral wool. Y. 1

1 acoustic tile consisting of body particles bonded together with an adhesive comprising an alkali silicate containing rubber substantially uniformly dispersed throughout to form in- L tercommunicating channels and pores between said'bodyparticles, said adhesive comprising the product resulting from the drying of an`alkali silicate solutioncontaining a relatively small amount of rubber latex and a silica gel uniformly dispersed throughout, said silica gel having been formed insitu by ,the reaction of an alkali silicouoride on said alkali silicate solution.

, 4. The acoustic tile of claim 3 in which the 125 alkali silicate is lsodium silicate and the alkali '1: silicoiiuoride issodium silicouoride. Y

g5.. The acoustic tile of claim 3 in which the alkali silicate is sodium silicate, the alkali silicouoride is sodium silioouoride, and the body particles are a porous re-resisting-aggregate. j 6. The acoustic tile of claim 1 in which vless than 10% of rubber is-dispersed in the dried alkali' silicate adhesive.

Y'1. The Vacoustic tile of claim 3 in ,which the 135 alkali silicate is sodium silicate, the alkali silif cofluoride is sodium silicouoride and in which 2% to 5% of rubber latex and less than 10% of solid sodium silicouoride is dispersed in the alkali silicate solution used as the wet adhesive. 14g 8. I'he method for making a resilient acoustic tile -which comprises preparing an adhesive comprising a lconcentrated alkali silicate solutionA containing not more than 12 .percent of rubber xedly dispersed therein by means of a silica gel formed in situ, mixing said adhesive f. with bodyparticles in such proportion that the dried -nishedtile will have intercommunicating pores and channels, forming a tile of said mixture, and drying saidtile,

Examiner s lar-aw.:-

9. The method of claim 8 in which'alklfsilicoiluoride is the substance which is added to the alkali silicate solution to gel it.

10. The method of claim 8 in which sodium silicoiiuoride is the substance which is added and sodium silicate is the alkali silicate, and in which 2 to 5 percent of rubber latex and less than 10v percent of sodium silicouoride is used, said percentages being based on the weight of the sodium silicate solution used.

11. An acoustic tile consisting of body particles bonded together with an adhesive comprising an alkali silicate containing rubber um'- formLv dispersed throughout to form intercommunicating channels and pores between said body particles, said adhesive comprising the product resulting from the drying of a concentrated alkali silicate solution containing not more than 12 percent of rubber and a silica gel uniformly dispersed therethrough, said .silica gel being formed in situ by the reaction of not more than 10 percent of an alkali silicouoride \on said alkali silicate solution.

12. The method for making a resilient .acoustic tile which comprises preparing an ad- -ahesive comprising a. concentrated alkali silicate hesiye with body particles in such proportion that the dried iinished tile will have intercommunicating pores and channels, forming a tile of said mixture and drying said tile. ,f

13. An acoustic tile consisting of body parti- -cles bonded together with an adhesive comprising an alkali silicate containing rubber uniformly dispersed throughout to form intercommunicating channels and pores between said body particles, said adhesive comprising the product resulting from the drying of a concentrated alkali silicate solution containing from 0.6 to 6 percent of rubber and a silica gel uniformly dispersed therethrough, said silica gel being formed in situ by the reaction of from 1 to 5 percent of an alkali silicofluoride on said alkali silicate solution.

14. The method for making aresilient acoustic tile which -comprises preparing an adhesive comprising a concentrated alkali silicate solution containing not more than 6 percent of rubber ilxedLv dispersed therein by-means of a silica gel formed in situ, mixing said adhesive with body particles in such proportion that the dried nished tile will have intercommunicating pores and channels, forming a tile of said mixture an drying said tile.

` MAX H. KLIEFOTH.

CERTIFICATE 0F CORRECTION.' p v Patent-N0. 1,976,946. p N f october 16, 1934.

` MAX n. KLIEFom *i E lt is hereby certified that error appears in the printed specification of the ,f-

above numbered patent requiring correction as follows: Page 2, line 103, claim 1, for "a" read an; line 119, claim 3, for "an" read a concentrated; and lines t 120 and 121, of said claim 3, for the words "a relatiely small amount of rubber latex" read not more than l2 percent of rubber; and that the said Letters Patent should be read with these corrections therein that the -same -may conform to the record of the case in the Patent Office. v

f Signed and sealed this 13th day of November, A. D. 1934.

Leslie Frazer (Seal) l 1 Acting 'Commissioner of Patents. 

